High - power yb - doped fiber lasers have caused particular interest as a reliable , efficient and compact , low cost source for a variety of applications in industry , printers , free - space communication , national defense and so on . the dissertation focuses on the yb - doped double - clad fiber lasers , the fiber bragg gratings in double - clad fiber , the fiber lasers based on double - clad fiber grating and pumping methods . the research works in detail are shown as follows : 1 本项研究工作结合国家自然科学重点基金和国家八六三项目,研究内容是对包层泵浦的掺镱光纤器件进行研究,从理论和实验两方面对掺镱双包层光纤激光器、放大器,双包层光纤bragg光栅及其选频的光纤激光器,泵浦耦合方式等进行研究,取得了良好的结果。
Owing to the limitation of the ray method in analyzing the field distribution and transmit power of optical waves in fibers we decide to apply waveguide theory for analyzing dcf with truncated inner cladding in an at tempt to find out the divergences of different types of dcf with truncated inner cladding in absorption efficiency in unit distance 由于射线法在分析光波在光纤中的场分布、传播功率等情况时有其局限性，因此，文章改用波动理论对缺陷型内包层双包层光纤进行分析，试图找出不同类型的缺陷型内包层双包层光纤单位距离内吸收效率的差异。
